m103 code 17
 

i have a 91 300e with the k jet fuel injection system i have been getting code 17 oxygen sensor signal shorted or improbable i hooked a voltmeter to the lambda sensor lead under the pass carpet and drove the car it varies from .025 to .950 volts i see .03 to .05 v for normal driving vhen you let off on the throttle it runs to .85-.95volts i check lambda at pin 3 under the hood using a dwell meter and get varying around 60% (slightly lean) when i run engine to 2500 rpm the lambda runs to 80-85%(very lean) if i set lambda to around 50% i get 0Acenter at the eha but the car runs rough at around 60% it runs best but not quite right i have looked for vac leaks and have replaced all injectors and associated injector seals(definate improvement they were getting sticky leaky trying to clean the old ones didnt help) i replaced all the rubber hoses for the cold start valve and to the air cleaner and to the valve cover when i did the valve job at around 210000 mi it now has 268000mi i still like the car! any ideas?

Perhaps its time for a new oxygen sensor?

^ I agree, time to replace it.

You can use the 1990 Ford Mustang GT (302 motor) oxygen sensor and just splice the wires. This is what I did on my 190E 3.0. I used a universal one on my 420SEL.

^ I used the Bosch Mustang sensor myself. $40 at any random McParts store beats the hell out of $100 or more at a dealer or European auto parts specialist.

There will without a doubt be those who will chime in and denounce me but the Mustang part is the exact same thing aside from the end connector and about $60.